Existing HVAC and/or refrigeration systems typically include one or more motor drives, such as motor drives used to drive compressors and fans, which are used to condition, heat, cool, ventilate or otherwise control the conditions of a space. In existing conventional systems, motor drives in the HVAC and/or refrigeration system are supplied power via a power correction factor (PFC) subsystem. The PFC subsystem may increase the ratio between useful power transmitted and total power transmitted to the HVAC and/or refrigeration system. Conventionally, a PFC subsystem provides a constant bus voltage regardless of the load on the motor drives of the HVAC and/or refrigeration system. In light load situations at the HVAC and/or refrigeration system requiring less power, the PFC subsystem maintaining the constant bus voltage results in losses at the PFC subsystem and significant magnetic core losses in the motor drives of the HVAC and/or refrigeration system. Moreover, the constant bus voltage must be set high enough to support the peak voltages on the motor drive terminals. Thus, existing conventional systems sacrifice efficiency and resources at lighter loads by maintaining a high bus voltage to provide sufficient power to the motor drives for peak operation.